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Discussion Starter · #1 ·
Hello

Could somebody please tell me how much i would need skim off a standard 1.8 k series head , to bring compression's down to the Same or a little lower that the compression ratio used for the 1.8 turbo k series ??
 

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Discussion Starter · #4 ·
Am i missing somthing , i thought the turbo engine had a lower compression ratio than the standard K series , i also thought if i wanted to run more boost you have to lower the comprresion ratio ?
so going by whats been said , if i want to run more boost then i can put a normal head on a turbo bottom end and run a bit more than standard boost ??
 

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The drop in compression ratio is often done by putting a dish in the top of the pistons. I don't know if they do this on the K series engine though.
 

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as said, skimming will raise C/R

you need either a thicker HG or there are places that "shot blast" the top of the piston, this compacts the top surface and hardens it, giving slightly stronger pistons and slightly lower C/R.

Best way is to get a set of low compression pistons made up though
 

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Discussion Starter · #7 ·
so if i have a turbo bottom end and fit a late standard 1.8 head would that make the same compression ratio as a 1.8 T ? and if i fit a thiker gasket with a shim i can run more boost is that right ?

does anybody know what rover did to lower the compression ratio on the 1.8T ?
 

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so if i have a turbo bottom end and fit a late standard 1.8 head would that make the same compression ratio as a 1.8 T ? and if i fit a thiker gasket with a shim i can run more boost is that right ?

does anybody know what rover did to lower the compression ratio on the 1.8T ?
Shorter rods.

You can lower the CR by excavating material from the combustion chamber and by using a shim between the gasket and the head (similar to the shim used in the latest Landroiver MLS gasket.) These shims can be had up to 1mm thick. With some material taken from the chambers and a thick shim you should be able to lower the CR by around 1.5-2 points.

Dave
 

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Discussion Starter · #9 ·
Thank you for that ,
i thought that the valves were shoter and the lifters are , i wonder if that shorter lifters makes a diffrence too ??

what would happen if i put a set of normal 1.8 valvs and lifter in a 1.8 t head ?
would the valves hit the pistons or would it be o.k .
 

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Pop, I doubt that there any differences in valve or lifter length, if there were it would make no difference to the CR, but the valve springs might go coilbound.

Dave
 

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Discussion Starter · #11 · (Edited)
Hi
After reading back over the post i think i should try to be a little more clear about what i really need to know

i have a 1.8 turbo bottom end but it needs a head , i can't find a 1.8 turbo head anywhere and if i did it would probably cost the Earth , so i am going to use a normal 1.8 head , would there be an advantage using a tf 135 head , i would like to run 10psi of boost , so what actual needs to be done to engine ?
 

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Hi
After reading back over the post i think i should try to be a little more clear about what i really need to know

i have a 1.8 turbo bottom end but it needs a head , i can't find a 1.8 turbo head anywhere and if i did it would probably cost the Earth , so i am going to use a normal 1.8 head , would there be an advantage using a tf 135 head , i would like to run 10psi of boost , so what actual needs to be done to engine ?
The TF135 has marginally better cams so it could give an advantage, I would lower the CR with a 1mm shim if you want to run 10PSI.

Dave
 

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Just a thought. I remember reading about VVC head having better ports/valves. Would a VVC head with MGTF 135 cams be any good?
 

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Just a thought. I remember reading about VVC head having better ports/valves. Would a VVC head with MGTF 135 cams be any good?

The TF 135 cams wont fit the VVC head, to fit a VVC head you will need a VVC blanking kit, a set of VVC plug top coils (if you are EU3), a pair of cams (or at least an inlet cam) from Piper, some work to your cam sensor since it wont reach the cam on the VVC head as the ladder is taller. You will also need a VVC plenum with some mods for the MAP sensor, a VVC rear cover for the front cambelt, and a manual tensioner and belt.

Dave
 

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Discussion Starter · #15 ·
Just what i wanted to hear dave , do you know where i can get a 1mm shim from ?


as for the vcc head idea , couldn't it use 2 vvc exhaust cams ?.
 

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Just what i wanted to hear dave , do you know where i can get a 1mm shim from ?


as for the vcc head idea , couldn't it use 2 vvc exhaust cams ?.
Gosnays do 1mm shims.

Err, exactly how do you think two VVC exhaust cams would work? The inlet cam is completely different on the VVC, you would require a blanking kit and new cam with larger journals, the exhaust cam is the same as a regular cam WRT journal size but has an extra ring and roll pin on the rear to drive the VVC rear belt.

You could use two VVC exhaust cams in a *regular* head since the profile is the same as the TF135, but these are not thick on the ground.

Dave
 

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Hello
Sorry to bring up an old thred , but i did a search and this thread poped up ,
thank you for the adviced in this thread , i have ordered a shim from gosneys , i have the turbo bottom end also ,
i would like to know if i can only use a low port head or could i use a high port head and how i can tell the diffrence before i buy
all you help and advice would be appreciated
 
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